Blow-out preventer



April 14, MELOTT BLOW-OUT PREVENTER Filed Sept. '7, 1927 2 Sheets-Sheetl April 14, 1931. J. MELOTT BLOW- OUT PREVENTER 2 Sheets-Sheet 2 FiledSept. '7. 1927 ./7 xxx Patented Apr. 114, IQBE UNITED STATES PATENTOFFICE JOHN KELOT'I', OF LOS ANGELES, CALIFORNIA BLOW-OUT PREVENTERApplication filed September 7,- 1927. Serial No. 218,023.

My invention is a blow out preventer' for oil well work to prevent ablow out when drilling, or in other similar operations.

An object of my invention is a blow out preventer having a plurality ofslips slidable upwardly and inwardly so that if a blow out occurs ina'well, these slips may be controlled to give the initial lift intoposition, and the greater the pressure of the gas in the well, thetighter the closure made by the blow out preventer; thereby using thepressure in theuwell as the main element inseaung off the we Anotherobject of my invention is in a. blow out preventer using a plurality ofoutwardly and inwardly moving slips having rubber or the like packing toengage between a stationary seat and a drill pipe to provide a simplemanually controlled mechanism for releasing the slips from the normalinactlve lower position, and giving these an initial upward and inwardmovement in the proper position to be actuated by the pressure of thegas in the well, and forming a tight seal between the seat and the drillpipe.

Another object of my invention is the construction of blow out preventerhaving a plurality of upwardly and inwardly movable slips, such slipsbeing arranged whereby the slushing mud used'in sloshing the well willnot interfere with the operation of the slips.

In constructin my invention I apply a suitable head to t e top of a well.casing and on this head I mount a seat for the blow out preventer, thisseat being of substantial construction and having an outwardly anddownwardly diverging inner wall, such wall being substantially a frustumof a cone with the apex upwardly. Slips of the proper shape to engagethe seat are mounted in the structure between the well casing cap andthe seat mounted thereon. These slips have a vertical surface formingpart of the cylinder, and

.an outwardly coned surface, a flat base, and

usually a short cylindrical outside wall. The

slips are covered on the conical face and on the inner cylindrical facewith rubber packing, or the like, to engage, respectively, the seat anda drill pipe, or other equipment.

In one form of my invention the slips are counterweighted by aheavyweight with cables connected to the top of the slips.

These cables pass over a suitable pulley systerm so that one weightfunctions to lift all of the slips into their closing position, Inanother arran ement, the slipsrest on a fiat metal ring and this ring isthrust upwardly by a plurality of thrust rods, such rods being elevatedby means of a heavy c0unter-weight with flexible cables.

In each of these constructions I use a manually operated latch which inone position holds the slips in their normal inoperative position, thatis, in their lowermost location, and on release, allows thecounter-weight to elevate the slips. In another construction I have thethrust rods which lift the slips actuated by a hydraulic, compressed airor steam cylinder piston system, such being manually controlled so thatthe slips may be quickly forced upwardly on indications that the well isabout to blow.

My invention will be more readily understood from the followingdescription and drawings, in which:

Figure 1 is a plan view of my invention taken substantially on the line1--1 of Fig. 2 in the direction of the arrows.

Figure 2 is a vertical section taken substantially on the line 22 ofFig. 1 in the direction of the arrows, showing a derrick floor with aturn-table thereon.

Figure 8 is a section somewhat similar to Fig. 2 of a modification inwhich thrust rodsv are used to elevate the slips connected tocounter-weights.

Figure 4 is a detail section on the line 4-4.- of Fig. 3 showin theinterconnection of the thrust ring and tie slips.

Figure 5 is a section somewhat similar to Fig. 3 of a furthermodification showing the thrust rods, thrust ring and slips beingelevated by a fluid operated system.

Figure 6 is a horizontal cross-section on the line 66 of Fig. 5 in thedirection of the arrows.

Figure 7 is a horizontal section on the line 7-7 of Fig. 2 in thedirection of the arrows showing the toggle connection for forcinguniform action of the slips.

Figure 8 is an irregular vertical detail on the line 88 of Fig. 7 in,the direction of the arrows. 1

In the construction shown in Fig. 1 and Fig. 2 a well casing isindicated by the numeral 11, having a substantial cap 12, this caphaving a horizontal flange 13. Slushing outlet pipes 14 are connected tothe cap and have control valves 15. Rotary. drill tubes 16 areillustrated as being used in the well, and on the floor 17 there is a"rotary rig or turn-table 18 which is of the usual character. Myinvention is intended to engage a drill pipe, or

the like, and prevent a blow out of the well, should the well begin togas.

In my invention I mount a heavy housing 19 which is bolted to the flange13 of the well cap. This housing preferably has a cylindrical large bore20, an upwardly and inwardly inclined seat '21, and upper vertical slots22. There are also a plurality of guide pins 23 which are secured to theflange 13 and extend upwardly and inwardly on an inclination parallel tothe seat 21.

A. plurality of slips24, of which four are shown, are fitted in thehousing. These slips have a flat base 25, an outer wall 26 concentric tothe wall 20, an inner surface 27 which is substantially on the samecurvature as the circumference of the drill pipe 16. The upwardly andinwardly inclined surface 28 is parallel to the seat 21 and the slipsalso preferably have a flat top 29.. Each of the slips has an internalpacking 30 fitted in a recess 31, and-an external packing 32. Thesepackings are preferably of rubber; There are also holes 33 toaccommodate the inclined pins 23.

A cable 34 is connected to each of the slips, the connection being byeyes 35, and each of these cables passes over a pulley 36 on the top ofthe housing, these pulleys extending inwardly of the small bore'22 androtate in vertical planes. There are also a series of guide pulleys 37mounted on studs 38 on top of the housing 19 and these operate on ahorizontal plane. One of the cables 39 passes over a guide pulley 40.All of these cables lead to a set of drums mounted on the shaft 42 whichhas a hand wheel 42, the shaft being supported on brackets 43. One ormore of the cables, after a few turns on the drums, has a vertical drop44 with a counter-weight 45. The hand wheel 42 may be used to'initiallystart the actuation of the slips or to give a binding tension on thecables when they are fully closed in.

The trip mechanism comprises a stop clamp 46 which is attached to thedrop cable 44 and this clamp is engaged by a bifurcated cam 47 connectedto the latch arm 48, this arm being mounted on a pivot pin 49 supportedon the bracket 50. A hand line 51 connects to the latch. The bifurcatedcam engages on both sides of the clamp 46.

The manner of operation of my invention pull these upwardly. In thiscondition the drilling operation may be carried on. For instance, arotary drill pipe may be used in the well, there being suflicientclearance for the couplings, the various drilling tools and the like.Should the well begin to blow, the operator pulls the hand line 51which, drawing down on the latch arm 48, rocks the bifurcated cam 47 onits pivot 49, thereby releasing the cam from the clamp 46, which allowsthe full weight of. the counterweight 45 to act on the slips. As thiscounterweight is materially greater than the weight of the slips, theslips are pulled upwardly and inwardly, the inclined seat 21 forcingthem inwardly so that the rubber packing 30 engages the side of a drillpipe and the packing 32 on the upper surface wedges against the seat,thus giving a gas and liquid tight joint and preventing blowing out ofthe well.

When it is desired to lower the slips again, the counterweight iselevated in any suitable manner, and the bifurcated cam fittedunderneath the clamp, and in this procedure the slips are guided intotheir position shown in Fig.2 by the inclined pins 23.

My blow out preventer as illustrated in Figs. 3 and 4 is constructedsubstantially as follows:

In this case the well casing'cap 12 is provided with a flange with aseries of openings 61 therethrough with stuffing boxes 62. The housing19 and the slips are substantially the same as illustrated in connectionwith Figs. 1 and 2. 'These slips rest on a ring 63 having a plurality ofradial slots 64, there being'one slot for each slip. The guide pins 23secured to the flange of the casing cap pass upwardly through the slot64 engaging in the slips. Thrust rods 65 extend upwardly through thepackings 62 and engage the lower surface of the ring 63. The lower endsof the thrust rods 65 bear on a sliding collar 65', this collar havingthe cables 66 secured thereto, all of which pass upwardly over guidepulleys 67 operating in vertical planes. Some of these cables extendover horizontal guide pulleys 68, these pulleys being mounted onbrackets 69 and 70 secured to the flange of the casing cap. All of thecables lead over drums 71 on a horizontal shaft 71' having ahand wheel71" on the shaft. The shaft is journaled in brackets 72. One or more ofthe cables after a turn on the drums is connected to a counter-weight73. The drop line 73 of the cable has a clamp construction similar tothat used in connection with Figs. 1 and 2.

In the operation of the device of Figs. 3 and 4 when the slips are intheir normal inoperative position, the ring 63 rests on top of theflange of the casing cap, the major portion of theweight of thecounterweight being supported by the cam-shaped latch, which. should thewell begin to blow, may be released and the counterweight will then acton the cables, lifting the collar and thrust rods, thus forcing the ring63 and the slips into the upward position shown in Fig. 3, therebygripping t e drill pipe or the like.

The construction of my invention as illustrated in Figs. 5 and 6 issubstantially 'as follows:

In this arrangement the casings, the slips and the thrust rodarrangement 65 for raisingthe slips are substantially the same as shownin Figs?) and 4. However, on the lower part of the well casing cap Ihave a plurality of cylinders 80. These cylinders have removable plugs81 at the base and have suitable packing 82 through which extend thethrust rods 83, such rods being connected to pistons 84 and beingequivalent to piston rods,

such rods extending upwardly into the housing and engaging the ringunderneath the slips. 7

The upper and lower ends of the cylinders are connected with pipes 85and 86 which are joined by a pipe 87 having a suitable threeway valvebeing connected to a source of supply 89, and the other to a discharge90. It is to be understood that all ofrthe cylinders are connected tothe same valve so that the manipulation thereof operates all the slipsin unison.

The manner of operation and functioning of the arrangement shown inFigs. 5 and 6 is substantially as follows:

The slips are normally resting in their lower position in the housingand disengaged from the drill pipe or the like. In this condition thepistons would occupy their lowermost position in the cylinders. When itis desired to raise the slips, the valve is operated, forcing eitherhydraulic fluid, steam or compressed air, or an equivalent power medium,into the cylinders below the pistons, thereby elevating the pistons.This causes the upward thrust of the thrust rods and lifts the slipsinto engagement with the drill pipe, thus effectively sealing the welland preventing a blow out.

Should the slips be jammed tight to the pipe, especially by the internalpressure in the well, and it is desiredto lower the slips, afterreleasing such pressure the valve may be operated in the oppositedirection, forcing the, power fluid into the upper part of the cylindersand depressing the pistons, the

power medium being forced out of the lower part of the'cylinders. 1 Itwill be noted in connection with Figs. 3 and 5 that the housing does notrequire any upper slots, as indicated by the numeral 22 I in Fig. 2. IThese upper slots may be eliminated from the construction of Fig. 2,provided the connection between the slips and the cable allows the slipsto be drawn upwardly and forced inwardly sufiiciently to engage a drillpipe. Also, if desired, the conical seat in the housing may extenddownwardly substantially to the flange of the well casing cap, the slipsbeing made to correspond with the internal shape of the houslng.

From the above description it will be seen that I have developed severalsimple forms of a blow out preventer using slips which may readily belifted into position to engage a suitable seat on a substantial housing,and to this end I may use either the force of gravity, as by acounterweight, or a positive impelling medium, such as steam, hydraulicor compressed air; also that the internal pressure. of the well acts tocause-a tighter seal, therefore, the greater the pressure in i of thearrangements shown and given in detail in Figs. 7 and 8. Each of theslips is "provided on its under surface with vertical recesses extendinginwardly from the side edges 96 of the slips. Toggle arms 97 are sccuredto pivot pins 98 or fitted in these recesses, and the free ends of theselinks are connected by a pivot, pin 99. These toggles occupy theposition shown in full lines in Fig. 7 when the slips are spread apartthe full distance.

When the slips are drawn together, even if the drill pipe is out ofcenter, the action of one slip in moving causes an action of thetoggles, thereby forcing all the slips to act in unison so that there isno danger of one slip jamming, either due to the seating arrangement forthe slips or to internal pressure in the well, because all the slips inbeing forced inwardly are also caused to act in unison; hence firmlyabutting together and giving a positive seal to the drill pipe.

An advantage of having the posltive control of the slips by the handwheels on the shafts having the drums over which the an upward andinward jam, thereby securing a tight seal.

It will be noted that the lower end of the slips, as shown in Figs. 3and 5, are outwardly and upwardly tapered so that when the ring 63 liftsthe slips, these have a tendency to slide inwardly over the inner edgeof these rings. 4

Another feature forming a tight seal with my blow-out preventer occursif a tool joint or collar comes into engagement with the lower surfaceof the slips, wl'iich action causes an upward wedging of the slips,effecting a tight seal above such tool joint or collar.

Various changesmay be made in the principles of my invention withoutdeparting from the spirit thereof, as set forth in the description,drawings and claims. Iclaim: 1 v- 1. A blow out preventer comprising incombination awell casing cap having a flange, a housing connectedthereto having a conical internal seat with the apex upwardly and havinga large bore below the seat and a smaller'boreabove the seat, aplurality of,

slips each having a flat base, an outer surface conforming substantiallyto a large bore, an inner surface conforming to a drill pipe, and upperinclined surfaces conforming to the said seat,vthe slips in theirinoperative position resting on their base on the flange with theirinner surfaces spaced from a drill pipe, and means to elevate saidslips, the seat en gaging the inclined surfaces and forcing the slipsinwardly with their inner surfaces enupwardly through-said openings andthe stufling boxes, a housing mounted 'on the flange having an internalconical seat with the apex upwardly, a plurality of slips mounted insaid housing, each slip having an upper inclined surface to conform tothe seat and an inner. vertical surface to engage a drill pipe, meansinterengaging the thrust rods and the slips, said slips in theirinoperative position being spaced from a drill pipe, and means toactuate said rods to elevate same and thrust upwardly on the slips, thesaid seat of the housing forcing the slips inwardly into engagement witha drill pipe, the means to elevate the thrust rods comprising a cableconnected to each rod, a counterweight connected to said cables, and alatch means interen aging with the cable and the counterweight when theslips are in their lower inoperative 'posltlon.

In testimonywhereof I have signed my name to this specification.

' JOHN MELOTT.

gaging a drill pipe, and pins forming a guide means mounted in thehousing and engaging holes in the slips to return the slips to theirnormal inoperative position, guiding said slips outwardly in theirdownward movement. I

v 2. A blow out preventer comprising in combination 'a well casinghaving-a horizontal flange,- a housing connected thereto having an innerinclined seat-with the apex upwardly, a large bore below .the'seat,inclined guide ins secured to the flange of the cap, a plurality ofslips each having guide holes to engage the said pins, the slips havinga base surface I to conform to the flange and having an upper surface toconform to the seat and an inner surface to conform to a drill pipe, thesurface of the slips engaging the seat having a resilient packing, theinner surface to engage the drill pipe having a resilient packing, saidslips in their. inoperative position resting on the flange and spacedfrom a drill pipe, and means to elevate said slips, the .seat of thehousing forcing the slips inwardly into en-' gagement with a drill pipe,said slips being adapted for maintenance in said position by an internalpressure in the well casing.

3. A blow out preventer, as claimed inclaim 2, the means to elevate theslips comprising flexible cables with a counterweight, and

means interengaging the slips and the cables with a latch engaging oneofthe, cables when

